/* -*- mode: C -*-  */
/* 
   IGraph library.
   Copyright (C) 2006-2012  Gabor Csardi <csardi.gabor@gmail.com>
   334 Harvard st, Cambridge MA, 02139 USA
   
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc.,  51 Franklin Street, Fifth Floor, Boston, MA 
   02110-1301 USA

*/

#include <igraph.h>

#include <stdlib.h>

void print_vector(igraph_vector_t *v) {
  long int i, l=igraph_vector_size(v);
  for (i=0; i<l; i++) {
    printf(" %li", (long int) VECTOR(*v)[i]);
  }
  printf("\n");
}

int check_evecs(const igraph_t *graph, const igraph_vector_ptr_t *vecs,
		const igraph_vector_ptr_t *evecs, int error_code) {

  igraph_bool_t directed=igraph_is_directed(graph);
  long int i, n=igraph_vector_ptr_size(vecs);
  if (igraph_vector_ptr_size(evecs) != n) { exit(error_code+1); }
  
  for (i=0; i<n; i++) {
    igraph_vector_t *vvec=VECTOR(*vecs)[i];
    igraph_vector_t *evec=VECTOR(*evecs)[i];
    long int j, n2=igraph_vector_size(evec);
    if (igraph_vector_size(vvec) == 0 && n2==0) { continue; }
    if (igraph_vector_size(vvec) != n2+1) { exit(error_code+2); }
    for (j=0; j<n2; j++) {
      long int edge=VECTOR(*evec)[j];
      long int from=VECTOR(*vvec)[j];
      long int to=VECTOR(*vvec)[j+1];
      if (directed) {
	if (from != IGRAPH_FROM(graph, edge) ||
	    to   != IGRAPH_TO  (graph, edge)) {
	  exit(error_code);
	}
      } else {
	long int from2=IGRAPH_FROM(graph, edge);
	long int to2=IGRAPH_TO(graph, edge);
	long int min1= from < to ? from : to;
	long int max1= from < to ? to : from;
	long int min2= from2 < to2 ? from2 : to2;
	long int max2= from2 < to2 ? to2 : from2;
	if (min1 != min2 || max1 != max2) { exit(error_code+3); }
      }
    }
  }

  return 0;
}

int main() {

  igraph_t g;
  igraph_vector_ptr_t vecs, evecs;
  igraph_vector_long_t pred, inbound;
  long int i;
  igraph_vs_t vs;

  igraph_ring(&g, 10, IGRAPH_DIRECTED, 0, 1);
  
  igraph_vector_ptr_init(&vecs, 5);
  igraph_vector_ptr_init(&evecs, 5);
  igraph_vector_long_init(&pred, 0);
  igraph_vector_long_init(&inbound, 0);

  for (i=0; i<igraph_vector_ptr_size(&vecs); i++) {
    VECTOR(vecs)[i] = calloc(1, sizeof(igraph_vector_t));
    igraph_vector_init(VECTOR(vecs)[i], 0);
    VECTOR(evecs)[i] = calloc(1, sizeof(igraph_vector_t));
    igraph_vector_init(VECTOR(evecs)[i], 0);
  }
  igraph_vs_vector_small(&vs, 1, 3, 5, 2, 1,  -1);
  
  igraph_get_shortest_paths(&g, &vecs, &evecs, 0, vs, IGRAPH_OUT, &pred, &inbound);

  check_evecs(&g, &vecs, &evecs, 10);
  
  for (i=0; i<igraph_vector_ptr_size(&vecs); i++) {
    print_vector(VECTOR(vecs)[i]);
    igraph_vector_destroy(VECTOR(vecs)[i]);
    free(VECTOR(vecs)[i]);
    igraph_vector_destroy(VECTOR(evecs)[i]);
    free(VECTOR(evecs)[i]);
  }

  igraph_vector_long_print(&pred);
  igraph_vector_long_print(&inbound);

  igraph_vector_ptr_destroy(&vecs);
  igraph_vector_ptr_destroy(&evecs);
  igraph_vector_long_destroy(&pred);
  igraph_vector_long_destroy(&inbound);
  igraph_vs_destroy(&vs);
  igraph_destroy(&g);

  if (!IGRAPH_FINALLY_STACK_EMPTY) return 1;
  
  return 0;
}
